TALLAHASSEE -- With crime at a 41-year low, Florida lawmakers were puzzled: why was the nation's third-largest prison system getting bigger?

Senate Democrats on Tuesday used a projected 5,000-inmate spike in the state's prison population to argue in a meeting with Republican leaders that bills weakening the mandatory-minimum sentences for non-violent drug offenses needed to be passed this year.

The most recent prison population estimates project Florida's corrections system population would grow from just over 102,225 this year to 106,793 by mid-2017. And the spike would come with a $58 million price-tag.

Democrats said it was a product of "mandatory minimum" sentences for drug offenses, and that Republicans needed to advance bills like SB 328 sponsored by Sen. Arthenia Joyner, D-Tampa, which would allow judges to waive the three-year mandatory sentences for first-offenses in drug arrests.

"Judges are hamstrung," Joyner said.

But Senate President Don Gaetz, R-Niceville, had another explanation -- Broward County.

With a new sheriff and judges, the lawmaker said it appeared the crackdown was driving up the statewide increase.

According to state economists, Broward led the state the increase in new prison commitments in the 2012-13 fiscal year, with new commitments increasing from 1,684 prisoners to 2,182, a29.6 percent spike.

That trend was continuing in the 2013-14 fiscal year, with Broward leading the state in the number of new prisoners it produced.

"The problem is Broward County," Gaetz said. "It's not a statewide problem. It looks like it's a one-county problem."

A handful of Republicans are also advancing bills this session to weaken sentencing for non-violent crimes. One bill, SB 360, sponsored by Sen. Rob Bradley, R-Flemming Island, which increases from 4 to 14 grams the minimum weight threshold for trafficking in oxycodone and hydrocodone -- reducing the number of people likely to be charged with drug trafficking.

"I think you're seeing a real interest in addressing some of those issues," said Senate President-designate Andy Gardiner, R-Orlando.

But Gaetz cautioned the Democratic caucus not to get too anxious to unwind the laws that may have contributed to the reduction in crimes.